@SeanO I would say that American art divorced American culture. Prior to WW2 artists were always closely linked to culture. Grant Wood’s American Gothic was a poignant commentary on American culture that still resonates with Americans and is continually recreated in an effort to document the continuous American cultural changes.
The Works Progress Administration/Federal Arts Projects created during the Great Depression, gave artists money to create art with no strings attached. They could do anything they wanted and the money would continue. Their work did not have to be good or appreciated by anyone, and at least in New York State, no control over the arts was ever exercised. This created an artistic relationship that had never existed before. Even Michelangelo and Da Vinci had patrons that had to like what they did or the money would be cut off.
When the WPA/FAP ended much of what was created ended up in second-hand shops and sold off for pennies. The artists continued to create Abstract Expressionism and when the critics rejected it the artists rejected anyone who did not understand their work. It was like a messy divorce.
So to answer your question, I don’t see American art as ahead or behind just separate and elitist. American art has lost its voice with most American’s who like yourself prefer realism or at least something they can connect with visually.
FYI: I am not an anti-Abstract Expressionist. I like much of the work these artists did, but that is looking back. In 1960 few Americans liked it. If after 50 years, something becomes acceptable to cultural tastes that does not mean it was ahead of its time. Perhaps we just got used to it.